Current-controlling mechanism for railway-motors.



A. B. STITZER. CURRENT CONTROLLING MEGHANISM FOR RAILWAY MOTORS.

APPLICATION FILED FEB. 18,1909.

Patented July 27, 1909.

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UNITED STATES PATENT OFFICE.

CURRENT-CONTROLLING MECHANISM FOR RAILWAY-MOTORS.

Specification of Letters Patent.

Patented July 27, 1909.

Application filed February 18, 1909. Serial No. 478,565.

To all whom it may concern:

Be it known that I, ARTHUR B. STITZER, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a new and useful Improvement in Current-Controlling Mechanism for Railway-Motors, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

In the operation of a four motor electric railway car, with the ordinary schemes of connection, the reverse cylinder is frequently damaged and the contact fingers sometimes burned to an extent that renders the reverser inoperative. Such damage can not be attributed to any ordinary conditions that are well recognized as an eflicient cause of excessive burning of switch contacts, and it has therefore been attributed to causes more or less obscure. I have discovered that the damage in question is produced when the reverser is turned from the forward to the reverse position and back again while the car is in motion and while, of course, the controller is in the off position. The reason why this operation, under the conditions stated, is highly urious to the reverse is as follows: If the armature of a series motor is revolving in either direction and working as amotor, and the source of supply disconnected and the connections to the armature (or field) reversed, it is in condition to act as a series generator, provided there is a closed connection and the direction. or rotation be maintained by the inertia of the moving parts or the momentum of the car. The direction of flow of the current through the field and armature will depend entirely upon the residual magnetism of the-fields. This local current once started will rapidly increase in value and seriously damage the contact fingers of the revcrser if it be returned to its original position while the car is moving.

The ordinary scheme of connections for a four motor car involves the maintenance of closed connections permitting the condition just explained to arise. That is, the motors are divided into two pairs or sets, each set being permanently connected in parallel when the current is shut off as well as at all positions of the controller. If, therefore, while the car is in motion, the connections to the armature be reversed, the terminals of one motor of each pair are bridged with the other motor of the same pair, and the conditions above described are therefore produced in a magnified form, as there are two sets of generators each consisting of two generators connected in series. 7 I The object of my invention is to prevent the damage in question and in accomplishing this object I eliminate the conditions above described by arranging the connections so that When the controller is moved to its off position the closed connections between the motors of a pair are disestablished and when moved to its first running position the connections are reestablished. I have devised several means by which this mode of operation may be effected, while otherwise permitting the regulation of the motors in any of the different ways found to be efficient in practice.

In one form of my invention, the ordinary construction of the controller is unchanged and the motor circuits and their connection to the fixed contacts of the controller not substantially altered except that they are normally open and are adapted to be closed by means exterior to, but controlled by, the controller; such means being arranged to be operated, to close or open the motor circuits when the controller is moved respectively from or to its on position, so that a local current cannot be developed in these motors acting as generators in case the armature or field connections are reversed. In another form of my invention, the construction of the controller and the connections. of the motor circuits to the controller are modified and rearranged so as to close the local circuits through the controller itself when the latter is moved to its first running position, and leave open one end of each armature and field circuit when the controller is moved to its off position. This latter form of my invention is not herein illustrated or described, as the same is set forth in another application filed of even date herewith, Serial No. 478,564, in which are also claims for the subject-matter common to both forms of the invention. The present invention is therefore limited to that form of the invention in which the opening or closing of the loop in which the motors of a set are arranged in parallel is effected by means external to the controller but which are under the control of the controller so that they are caused to act at the time the controller is moved to or from its off position to open or close the connection from the trolley through the resistances to the first set of parallel motor circuits. One embodiment of this form of my invention is herein shown and described, but it will be understoodthat' this embodiment of my invention is illustrative merely and that the construction shown may be modified by those skilled in the art without departure from the substance of my invention.

In the drawings, Figure 1 is a diagrammatic view of an embodiment of my invention representing the motors, the controller, the reverser, the motor circuits, the resistances, the devices for opening and closing the connection to the trolley and the motor circuits, and the auxiliary circuit controlling such devices; Fig. 2 is a detail diagrammatic view of said auxiliary circuit controlling devices and their electrical connections.

C represents the controller, whose cylinder or drum has on its periphery the contact plates 0 to a inclusive.

1 to 11 inclusive represent the stationary brushes adapted respectively to make contact with the plates 0 to a inclusive in the rotation of the controller.

a represents the conductor leading to brush 1.

.R represents the resistances, which are connected to brushes 3, 4, 5 and 7 by the Wires 1), and are adapted to be successively cut in and out by the controller in the usual manner.

V represents the reverser.

Ml, M M and M represent the four motors geared in rotation to the four axles of the car.

m, m represent the branch circuits in which the motors M and M are respectively included.

6 represents the connections between the resistances and the junction at one end of the motor circuits In and m f represents the connection between the junction at the other end of the motor circuits m and m and the brushes 9 and 10. The usual cutout switch (not shown) maybe interposed in e andf, but its presence or absence does not atl ect the operation of my invention.

m m, represent the branch circuits in which the motors M and M respectively included.

it represents the connection between the brush 8 and the motor circuits in and m and i the connection between said motor circuits and the brush 11, leading to ground. The usual cutout switch (not shown) may be interposed in h and 2".

ll brush 2 were connected to the resistances, the scheme 0'! connection, so lar as the same has been described, wouldhe a typical one, and it will he understood that there would be a permanent closed connection or loop through motors M and M and a permanentclosed connection or loop through motors M and ill, permitting the development of the dangerous local current described;

The embodiment of my invention shown in the drawings involves no change in the wiring or in the resistances beyond, first, connecting the resistances directly with the conductor a, instead of with brush 2, by means oi conr'luctor second, opening the main circuit in the conductor 7c and also in the two loops including respectively the two pairs or sets 01" motors (as shoiri'i, in circuits m and in); and third, establishing an auxiliary or shunt circuit connecting brush 2 to ground and in tor-posing therein contactors by means of wnich the closing of the circuit in 7c, m and in is eliected when the controller moves from its otl position to its first running position. The contactors nay be connected so as to open and close the circuit including the trio motors normally connected in parallel. any desired point.

The contactors may 9c of any lrn own type. The same are shown as each comprising a solen oid [whose core carries bridge pieces 17, and 0 adapted to respectively bridge the contacts a and n and the contacts 0 and 0 The several contactors are represented by T, T an T the first being interposed in 7c, the second. in m and the third in n24. At each contactor the working circuit is made and broken at the contacts 0 and 0 and the auxiliary or shunt cin lit at the contacts n and n The auxiliary or shunt circuit is arranged as follows: From brush 2 of the controller a vrire p extends to the contact n of contactor T. A resistance r is iterposed in p. A conductor p, in which is inserted a resistance 1' extends from contact n of contactor T to contact a of contactor T. r is a resistance inserted in shunt between conductors p and p. A conductor 79 in which is inserted a resistance r extends from contact n of contactor T to contact 12. oi conh ctor A conductor p extends from contact n of contactor T to one end of the coil Z of contactor T. This coil is connected at its other end to the corresponding;' contact if, which is also connected by vaire 71 with one end of the coil Z of contactor T. The latter coil is connected at its other end to the corresponding contact 91 The coil of contactor T is connected at one end to the corresponding contact a and at the other end to ground. Resistanc'es r and 1' preferably of less power than the coils of contactors T and T al though they may be 01' the same or greater power or may be entirely omitted.

Normally, when the controller is at its oil position, the bridge-pieces n of the several 1;

contactors connect the contacts n and n closing the auxiliary circuit except at the controller, and the bridge pieces 0 are out of contact with contacts 0 and 0 opening the Working circuit through the contactors. In

moving the controller to the first running position, brushes 1, 8 and 9 contact with their corresponding contact plates on the con troller and then brush 2 contacts with plate 0 This closes the auxiliary circuit through a, brush 1, plates 0 and brush 2, conductors p, p, p, and coil of contactor T to ground. The coil of T is thus energized and its solenoid m moves the bridge piece n away from n and n and the bridge piece 0 into contact with 0 and 0 thus closing the motor circuit or. The circuit through 19 being now broken, the current passes from contact of contactor T through the coil thereof, through wire 19 through the coil of contactor T to ground. The coil of T is thus energized which opens the auxiliary circuit at the corresponding contacts a and n and closes the motor circuit m The circuit through 19 being new broken, the current passes from contact 72 of contactor T through the coil thereof, Wire 29, coil of contactor T, wire 9 and coil of contactor T to ground. The coil of T is thus energized, which closes the working circuit through in and shunts the current of the auxiliary circuit through resistance g, the current then passing, as be fore, through the coil of contactor T, wire p coil of contactor T, wire p and coil of contactor T to ground. The working circuit is now closed, in multiple through the' motors of each set and in series through the two sets, from trolley to ground; the current from the resistances passing through 6, motor circuits m and m in multiple, thence through f to brushes 9 and 10, contact plates c and c thence through h and in multiple through m and m to t, and thence to brush 11 and ground. In this position, as in the other running positions of the controller cylinder, the passage of the working circuit from the resistances to ground does not differ from that incident to known schemes of connections.

When the controller is moved from the first running position to the off position, the auxiliary circuit is first broken, denergizing the coils of all the contactors, and permitting the cores of the solenoids Z to return to their original positions and open the working circuits in 7c, m and m and then the working circuit is broken at the brushes 1, 8 and 9. It will be obvious that when the controller is in an oil position and the reverser is operated (which, in the modern controlling systems, is the only position of the controller that allows the reverser to be moved) the local circuit M, M connecting the motors 1N and M in parallel, is open at the contactor T, while the local circuit m or, connecting the motors M and M in parallel, is open at the contactor Under these conditions, of course, no closed loop circuit through the motors of a set can be established.

W hen, in the claims, I refer to the contactor, I intend to include any electrically controlled device operating like the contactor to make or break the circuit, as the particular construction of the contactors herein described is neither novel with me nor essential to the practical execution of my invention.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is 1. The combination with a set of motors and a controller, of an electric circuit in which said motors are normally arranged in parallel, and means exterior to, and controlled by, the controller to open and close the circuit at a point in the circuit including the several motors.

' 2. The combination with a set of motors and a controller, of an electric circuit in which said motors are normally arranged in parallel, a contactor exterior to the controller to open and close the circuit at a point in the circuit including the several motors, an auxiliary circuit in which said contactor is included, and means whereby the controller controls the auxiliary circuit.

3. The combination with a set of motors and a controller, of an electric circuit in which said motors are normally arranged in parallel, a controller brush to which said circuit is connected, a second controller brush, an auxiliary circuit connected to the second brush, a contactor in said auxiliary circuit adapted to open and close the working circuit at a point in the circuit including the several motors, and movable connected plates on the controller adapted to engage said brushes respectively.

4. The combination with a set of motors and a controller, of an electric circuit including a loop in which said motors are normally arranged in parallel, and means exterior to, and controlled by, the controller to open and close the circuit at a point in the loop including the several motors and also at a point outside the loop to open or close the connection to the source of supply.

5. The combination with a set of motors and a controller, of an electric circuit including a loop in which said motors are normally arranged in )arallel, a contactor exterior to the controller to open and close the circuit at point in the loop including the several motors, a contactor exterior to the controller to open and close the circuit at a point in advance of said loop, an auxiliary circuit including said contactors, and means whereby the controller controls the auxiliary circuit.

6. The combination with set of motors and a controller, of an electric circuit including a loop in which said motors are normally arranged in )arallel, a contactor exterior to the controller to open and close the circuit at a point in the loop including the several motors, a contactor exterior to the controller to open and close the circuit at a point in advance of said loop, a controller brush to which said circuit is connected, a second controller brush, an auxiliary circuit, connected to the second brush, in which said contactors are included, and movable connected plates on the controller adapted to engage said brushes respectively.

7. The combination with a set of motors, of a source of electric supply, an electric circuit, branches, arranged in multiple in the circuit, in which said motors are respectively included, a controller, and means exterior to and controlled by the controller to admit or cut oil current from the source of supply and substantially simultaneously close or open the branch circuits including the motors.

8. The combination with a set of motors, of motor circuits arranged in parallel each of which includes the armature and field of a motor in series, forming a loop circuit including the fields and armatures of the motors of the set, a reverser interposed in the several circuits and adapted when operated to reverse the current through one element ol each motor, a controller, said motor circuits being open at a point in the loop including the several motor circuits when the controller is at its oil position, and means exterior to and controlled by the controller to close the circuit at said point.

9. The combination with a set of motors,

oi an electric circuit, resistances in the cir-.

cuit, branches, in the circuit beyond the re sistances, in which said motors are respectively included, a controller, and means exterior to and controlled by the controller, in moving to or from its off position, to open or close the circuit in front of the resistances and in the branch circuits.

10. The combination with a set of motors, oil an electric circuit, resistances in the circuit, branches, in the circuit beyond the resistances, in which said motors are respec tively included, a reverser interposed in said branches, a contactor inserted in one of the branch circuits, contactor inserted in the circuit in front or the resistances, said contactors each controlling the opening or clos ing of the circuit at their points of location, an auxiliary circuit including said contactors, and a controller adapted, in moving to or from its oil position, to control said auxiliary circuit to cause said contactors to operate.

11. The combination with a set of motors, of an electric circuit, resistances in the circuit, branches, in the circuit beyond the resistances, in. which said motors are respectively included, a reverser interposed in said branches, a contactor inserted in one of the branch circuits and controlling the opening or closing of the circuit at that point, an auxiliary circuit including the contactor,

and a controller adapted, in moving to or from its off position, to control said auxiliary circuit to cause said contactor to operate and simultaneously therewith to open or close the Working circuit in front of said resistances.

12. The combination with a plurality of sets of motors, of an electric circuit in which the motors of each set are arranged normally in multiple, a controller, and means external to the controller and controlled thereby to open and close the circuit at a point in that part of the circuit including a set of motors.

13. The combination with a plurality of sets of motors, or an. electric circuit in which the motors of each set are arranged in a loop permitting their operation in multiple, contactors external to the controller to open. and close the circuit at points in the respective loops including said sets respectively, an auxiliary circuit in which said contactors are included, and means whereby the con troller controls the auxiliary circuit.

14. The combination with a plurality of sets of motors, of an electric circuit in which the motors of each set are normally arranged to the controller and controlled thereby, in

its movement from or to its off position, to admit or cut oil current to the circuit and to close or open the circuit at a point in part of the circuit including a set of motors.

15. The combination with. a plurality of sets of motors, of a source of current supply, resistances, a connection from the source of supply to the resistances, parallel circuits from the resistances through the motors of one set, parallel circuits through the motors of the other set, a reverser interposed in the several circuits and adapted to be operated to reverse the current through one element of each motor, a controller, and means external to and operated by the controller, in its movement to or from its oil position, to

open or close theconnection between. the

source of supply and the resistances and to open or close connection in the loop including the motor circuits of each set.

16. The combination with a plurality of sets of motors, of a source of current supply, resistances, a connection from the source of supply to the resistances, parallel circuits from the resistances through the motors of one set, parallel circuits through the motors of the other set, a reverser interposed in the several circuits and adapted to be operated to reverse the current through one element of each motor, contactor-s one interposed in the circuit in front of the resistances, and one interposed in set of parallel circuits including a set of motors, a controller, and means controlled thereby, in moving to or from its oil position, to operate said contactors to open or close the circuit at the several points.

\ from the resistances through the motors of one set, parallel circuits through the motors of the other set, a reverser interposed in the several circuits and adapted to be operated to reverse the current through one element of each motor, contactors, one interposed in set of parallel circuits including a set of motors, a controller, and means controlled thereby to operate said contactors to open or close the circuit in each loop and substanr. tiall simultaneousl therewith to 0 en or y J :9

close the circuit at a point in front of the resistances.

18. The combination With a plurality of sets of motors and a controller, of an electric circuit in which each set of motors is normally arranged in parallel, a contactor in each part of the circuit including a set of motors, and means controlled by the controller in moving from its oil to its first running position to operate said contactors successively.

19. The combination With a plurality of sets of motors and a controller, of an electric circuit in Which each set of motors is normally arranged in parallel, a contactor in each loop including a set of motors; each contactor comprising a coil, a bridge piece actuated thereby, and contacts connected by the bridge piece an auxiliary circuit comprisinga connection to one contact of one contactor, a

connection from the other contact to the coil of said contactor and to one contact of the other contactor, a connection from the other contact of the second contactor to the coil thereof and to the coil of the first contactor, and a connection to ground from the coil of the second contactor, and means operated by the controller to connect the auxiliary circuit to the main circuit in moving from its oil to the first running position.

In testimony of Which invention, I have hereunto set my hand, at Philadelphia, on this 11th day of February, 1909.

ARTHUR B. STITZER.

Witnesses FOREST E. ALTEMUs, CHAS. T. MYERS. 

